Month: February 2016

The Concept Of Mars Colonisation

There is a lot of speculation about possible human colonisation in the Red Planet. There are many studies being conducted to confirm and make it a reality. The presence of water on the planet and the look and feel of its surface conditions make it seem the most hospitable in comparison to the other planets. Apart from Venus, Mars is the only other planet that requires less energy per unit mass to reach from our mother Earth. Though it seems that colonisation of Mars is possible there are a lot of other challenges.

Mars’s similarity to Earth

Though Venus is considered the sister planet of Earth because of its size, surface gravity and bulk composition, the similarities Mars has to Earth make it more appealing for colonisation. A few of the similarities are enumerated below:

· Human habitation conditions

The conditions such as temperature and atmospheric pressure are very close to that of Earth however the air pressure is very low along with low oxygen content. This brings up the requirement for complex and artificial life-support systems to make colonisation a reality.

· Radiation

The absence of a magnetic field in Mars along with a very thin atmosphere allows a lot of ionizing radiation enters Mars. Though a long time exposure to such radiation can cause harm it was also found that living underground may reduce this radiation exposure to a great extent.

· Transportation

One would need less energy per unit mass to reach Mars from Earth than from any other planet apart from Venus. As of now it is identified that going to Mars requires on to travel around 9 months in space. However this time can be shortened to 6 months by using modified trajectories which use a high amount of energy and fuel. This requirement of large amounts of fuel needs high delta-v which is the energy per unit mass and is not possible using chemical rockets. However, this increased delta-v is possible using advanced technology of spacecraft propulsion.

The required equipment

The concept of Mars colonisation will require a lot of equipment for sustaining life. Equipment that help in providing services to mankind as well as equipment needed for production of food, water and energy including oxygen will be necessary.

Settlement locations

The polar regions of Mars are considered to be good settlement spots as the presence of polar ice has been noted. Equatorial regions are considered good points as they have natural caves which could help shield humans from radiation.

Sterilizing human missions to this extent seems to be almost an impossible task because humans are hosts to a lot of microorganisms. The most viable option is containment. There is the possibility of back contamination to Earth in case they become carriers of microorganisms.

There are many theories of colonising mars. The human race is an intelligent lot and will in fact come up with a viable plan soon with ideas on transforming mars.

Heat Transfer

The sun is the primary source of heat. It is defined as the energy in transit. The rate of its transfer is variable from substance to substance. It can be conducted rapidly through the conductors. Metals such as silver, copper are good conductors. Cloth, wood, air, glass, wool, distilled water, etc are bad conductors. It is conducted very slowly through the bad conductors.

The conductivity of substances is directly proportional to the magnitude of free electrons. When any substance is heated, the free electrons acquire the kinetic energy and thus move towards the remaining cooler locations. The heat energy would be transferred from one atom to the other atom due to their vibrations in the shape of waves. Hence, the atoms do take an active role in the process of transfer of heat. This method of transmission is known as conduction.

The woolen textile materials do contain very fine pore spaces. Both the air and the wool are very bad conductors of heat. Hence, the woollen clothes are being used to maintain the warm during cold seasons. The bricks are bad conductors of heat. Hence, thick walls are constructed in building the cold storage rooms. Metal cookers are fitted with ebonite handles to avoid the heat transfer.

Medium is required to transfer heat by convection. The fluids are heated mainly by this process. The heated particles themselves transfer heat. The liquid or gas particles do move to other locations after acquiring heat. The remaining particles move to their place to acquire heat. Thus the convection currents are set up.

The air which is exhaled does become lighter and thus rises up. It moves out through the ventilators. Similarly, the colder and the fresh air from outside does enter the room to take its place. Thus a convection current would be set up.

The heat does transfer in the form of electromagnetic waves in radiation. Heat radiation can also be termed as infrared rays. Hence, the properties of radiated heat are similar to light. But the wavelength of heat radiation is higher than the light radiation. The radiant heat does travel with the speed of light. Medium is not required in this process of heat transfer. In other words, heat radiation can travel through vacuum.

The heat radiations can travel in all directions, but in straight lines. When a person sits around any fire, he would feel heat all around equally. Heat transfer is the fastest in the case of radiation.

The radiation rate from a body does depend up on the nature, area, and also the temperature of its surface. Different types of surfaces maintained at the same temperature, do emit variable amounts of heat energy.

In a thermos flask, the vacuum between its walls does prevent the transfer of heat either by conduction or by convection. Silver lining does prevent the heat transfer by radiation. It also does reflect back the hot radiations from both outside and inside. A meagre amount of heat would be transferred by conduction through a thin glass wall at the neck and also through the bad conducting cork.

Some Fun Filled Science Experiments

Science can be fun when demonstrated experimentally. Below are a few fun-filled experiments that help understand certain concepts.

The Anti-gravity wheel

A wheel weighing 19 kg is lifted overhead being held only at one end of a meter long bar attached to it. Though this seems an impossible task, Derek Muller performs this task by using only simple physics. This is done by applying gyroscopic precession which is torque induced precession. The wheel is made in a way that allows the wheel to rotate freely on application of an external force and the wheel rotates on an axis bar. The force applied is in the opposite direction to the axis bar. The wheel and the entire apparatus feels light to the person holding it when enough force is applied.

The Backwards Brain Bicycle

This experiment is a very good demonstration of the ability of the human brain to change and evolve so as to change neural pathways. The experiment actually makes the simple task of riding a bicycle look like a challenging mental task.

The bike is designed in such a way that when the handle bars are steered towards the right the wheel turns towards the left and the other way round. Since the front wheel turns to the opposite direction to where the handle bar is turned the rider fumbles when trying to ride this bike. On riding this bike for a good amount of time, it gets challenging to ride a traditional bike the way it is supposed to be ridden.

The riding of a traditional bike is made easy because of the cerebellum. This area of the brain is responsible for proper motor control, coordination and balance. Most of the automatic activities are controlled by the cerebellum and this is exactly why injury to this part can be alarming throwing the individual off-balance and completely impossible.

The Magnus effect

An effect produced where a spinning ball curves from its path is termed Magnus effect. When balls are hit the Magnus effect works when at the same time a spin is given. Golfers, soccer players use this effect to curve the path of the ball. The effect works in the following manner. When the ball that spins is moving through the air a boundary layer of air clings to the surface and spins along. This layer when moving collides with passing air on one side creating a high pressure area. One the other side the air moves in the same direction and so travels faster creating a low pressure area. This pressure difference creates a lift force called the Magnus force causing the ball to move from high pressure area to low pressure area.

The Gravitational Force

Gravitation is defined as a force of attraction between any two bodies. Gravity is also a force of attraction exerted by the earth upon a body on or near its surface. The weight of any object at any point in the space can be defined as the resultant gravitational force, which is acting on the object caused by all the remaining objects in the space.

The motions of all the heavenlThe Gravitational Forcey bodies have fascinated the ancient thinkers too. The invention of telescope by Galileo did facilitate the recording of the movements of astronomical bodies.

Sir Issac Newton could simplify the Kepler’s laws of planetary motion into a simple law and is termed as the law of universal gravitation. It was proved that his law is applicable not only for the heavenly bodies, but also for any two bodies in our universe.

He opined that the force of attraction between any two material objects in our universe is directly proportional to the product of their masses and also inversely proportional to the square of the distance between their centres. He could also derive several mathematical equations related to the gravitational force.

According to him, the gravitational force of attraction of any object towards the centre of the earth is equal to the weight of the object, w= mg.

The mass of any object is defined as the quantity of matter contained in it. It is constant and does not change from location to location. It can never be zero.

The earth does attract every object towards its centre. This attraction force does depend on the mass of the body and also the acceleration due to gravity at any specific location. Thus the weight of any object is the force with which it would be attracted towards the centre of the earth.

The acceleration generated b the force of attraction of the earth is termed as the acceleration due to gravity.

The falling of any object in air under the action of gravity by neglecting the air resistance can be termed as a free fall and the object is known as the freely falling body.

It was proved that in the absence of any air resistance, or in vacuum all the objects do fall at the same rate irrespective of the magnitude of their masses. But some early thinkers did assume that all the objects fall down at equal rates of velocity in the absence of air resistance!